A REGULAR VALUE OF COMPACT DEFORMATION

Sufficient conditions were given to assert that between any two Banach spaces over K, Fredholm mappings share at least one value in a specific open ball. The proof of the result is constructive and based upon continuation methods.     

Signaling-based path-segment protection in mesh optical networks

Path protections have become increasingly important for current mesh optical networks because fast restorations in generalized multiprotocol label switching(GMPLS) networks are uncertain.However,setting up additional disjoint paths to protect connections leads to more path setup blocking and signaling collisions.We analyze signaling collisions,path blocking and blocking probability,as well as calculate node-to-node blocking probabilities.A signaling-based path-segment protection(PSP) is proposed,which integrates segment protections and path protections as well as enhances the performance of path protections and ring protections.The setup of PSP connections causes less blocking probability than the setup of path protection connections in the simulations.     

紧凑式低温换热器研究进展

介绍了紧凑式低温换热器的研究进展,对低温换热器传热机理研究中所存在的问题以及新型低温换热器的研制进行了详细分析,对现有换热器优化设计方法进行了比较,给出了作者的一些观点,为低温换热器的设计及以后的进一步研究提供参考。     

周视监控全景镜头设计

利用ZEMAX光学软件设计了一种可用于周视监控的全景镜头,镜头由凹凸反射镜组和中继镜组组成,反射镜组使镜头获得大视场角,中继镜组将反射镜组所成的虚像投影到探测器上。该镜头有效焦距为0.97 mm,F数为1.5,垂直方向视场为65~95,水平方向视场为360,镜头工作在475 nm~750 nm波段,总长为69.7 mm。设计结果表明:系统全视场f 型畸变小于5 %,调制传递函数（MTF）值在空间频率为60 lp/mm时大于0.58,系统成像质量良好,可满足周视监控的使用要求。     

利用原子干涉仪实现高精度惯性测量

综述了目前国内外正积极研制的原子干涉仪.它是建立在激光冷却、囚禁与操控原子理论基础上,利用原子本身作为自由下落的"测试物体"来测量仪器所受到的惯性力.这种新型惯性敏感器能以前所未有的精度同时测量物体的旋转角速度和线性加速度,并可通过原子对抛技术实现两种量测量的区分,这已为诸多实验所验证.报道了国内外原子干涉仪的最新研制进展.原子干涉仪的紧凑性和长时稳定性将使其在惯性测量领域获得更广泛的工程应用.     

基于紧凑拉伸剪切结构的复合型疲劳裂纹扩展研究

针对含I-II型复合裂纹的紧凑拉伸剪切(CTS)试样,研究了不同加载角度下的裂纹扩展路径及裂纹扩展寿命,通过实验数据给出了适宜于CTS试样的等效应力强度因子关系式,并基于此提出了一种新的I-II型复合裂纹扩展模型。研究表明,CTS试样的裂纹沿与加载方向近垂直的方向扩展,基于Tanaka公式的等效应力强度因子更适合于本文CTS试件的裂纹扩展寿命评估。当加载角度处于0°~45°之间时,提出的复合型裂纹扩展模型预测误差控制在5.49%之内,验证了分析模型的可行性和准确性。     

Compact and high-energy diode-side-pumped Q-switched Nd:YAG slab laser system for space application

We develop a compact and high-energy Nd：YAG slab laser system consisting of an oscillator and an amplifier for space applications. The oscillator is a diode-side-pumped electro-optically Q-switched slab laser with a cross-Porro resonator. The KD＊P Pockels cell with a low driving voltage of 950 V is used to polarization output coupling. The amplifier is a Nd：YAG zigzag slab pumped at bounces. The maximum output pulse energy of 341 m3 with 13 ns pulse duration is obtained from the system at the repetition rate of 20 Hz and the beam quality factors are M2=3.1 and M2=3.5. The beam pointing stabilities of the laser system are 3.05μrad in the X-direction and 3.99 grad in the Y-direction, respectively.     

复合载荷下脆性材料紧凑拉伸试件疲劳裂纹的预制

本文针对脆性材料的紧凑拉伸（CT）试件,提出了在复合疲劳载荷作用下预制疲劳裂纹的新方法,用此方法预制出7060-T6铝合金的CT试件疲劳裂纹并测试其断裂韧性。由于采用了框架结构和螺旋结构在CT试件的两侧面施加压缩载荷,在拉伸疲劳载荷作用下产生与之方向相反的压缩疲劳载荷,形成复合疲劳载荷,引起应力强度因子范围ΔK的下降,导致裂纹扩展速率的降低,从而控制了疲劳预制裂纹长度。此压缩疲劳载荷值用贴电阻片方法和组成全桥原理测定出。在一定拉伸疲劳载荷和压缩载荷下,可成功地预制出所需的疲劳裂纹长度。     

一个新型电子直线加速器的预制研究

文中给出了对一个新型紧凑的电子直线加速器(linac)证明原理的研究结果.在该linac中,通过偏转磁场选择特定能量和相位的大功率速调管用毕束流,然后将它们注入到加速节中,同时使速调管工作在自激振荡状态,使传统linac上的许多部件都可以省去.据此建成的linac的结构简单、维护容易、性能良好、造价经济.因此实现这种具有众多优点的新型linac将有助于linac应用的推广.要实现这样的linac有许多关键的问题需要解决.电子束团的性能参量,如能量、电流、发射度,以及速调管自激振荡的频率稳定度等都必须符合加速的要求.文中给出的计算机模拟和实验结果都表明了实现这种新型的linac的可行性     

WEIGHTED COMPOSITION OPERATORS ON WEIGHTED DIRICHLET SPACES

We characterize the boundedness and compactness of weighted composition operators on weighted Dirichlet spaces in terms of Nevanlinna counting functions and Caxleson measure.